blob: 2eb12f13593db771987c9c4e7cd30c16515fcf11 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/binfmt_aout.c
3 *
4 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
5 */
6
7#include <linux/module.h>
8
9#include <linux/time.h>
10#include <linux/kernel.h>
11#include <linux/mm.h>
12#include <linux/mman.h>
13#include <linux/a.out.h>
14#include <linux/errno.h>
15#include <linux/signal.h>
16#include <linux/string.h>
17#include <linux/fs.h>
18#include <linux/file.h>
19#include <linux/stat.h>
20#include <linux/fcntl.h>
21#include <linux/ptrace.h>
22#include <linux/user.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/binfmts.h>
24#include <linux/personality.h>
25#include <linux/init.h>
Daisuke HATAYAMA088e7af2010-03-05 13:44:06 -080026#include <linux/coredump.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090027#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <asm/uaccess.h>
30#include <asm/cacheflush.h>
David Howells7fa30312008-02-08 04:19:28 -080031#include <asm/a.out-core.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs);
34static int load_aout_library(struct file*);
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080035static int aout_core_dump(struct coredump_params *cprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Linus Torvalds1da177e2005-04-16 15:20:36 -070037static struct linux_binfmt aout_format = {
38 .module = THIS_MODULE,
39 .load_binary = load_aout_binary,
40 .load_shlib = load_aout_library,
41 .core_dump = aout_core_dump,
42 .min_coredump = PAGE_SIZE
43};
44
45#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
46
47static int set_brk(unsigned long start, unsigned long end)
48{
49 start = PAGE_ALIGN(start);
50 end = PAGE_ALIGN(end);
51 if (end > start) {
52 unsigned long addr;
53 down_write(&current->mm->mmap_sem);
54 addr = do_brk(start, end - start);
55 up_write(&current->mm->mmap_sem);
56 if (BAD_ADDR(addr))
57 return addr;
58 }
59 return 0;
60}
61
62/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 * Routine writes a core dump image in the current directory.
64 * Currently only a stub-function.
65 *
66 * Note that setuid/setgid files won't make a core-dump if the uid/gid
67 * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
68 * field, which also makes sure the core-dumps won't be recursive if the
69 * dumping of the process results in another error..
70 */
71
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080072static int aout_core_dump(struct coredump_params *cprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073{
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080074 struct file *file = cprm->file;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 mm_segment_t fs;
76 int has_dumped = 0;
Borislav Petkov7731d9a2010-03-23 13:35:15 -070077 void __user *dump_start;
78 int dump_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 struct user dump;
Al Viro17580d72009-01-03 07:16:23 +000080#ifdef __alpha__
Borislav Petkov7731d9a2010-03-23 13:35:15 -070081# define START_DATA(u) ((void __user *)u.start_data)
Al Viro17580d72009-01-03 07:16:23 +000082#else
Borislav Petkov7731d9a2010-03-23 13:35:15 -070083# define START_DATA(u) ((void __user *)((u.u_tsize << PAGE_SHIFT) + \
84 u.start_code))
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#endif
Borislav Petkov7731d9a2010-03-23 13:35:15 -070086# define START_STACK(u) ((void __user *)u.start_stack)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88 fs = get_fs();
89 set_fs(KERNEL_DS);
90 has_dumped = 1;
91 current->flags |= PF_DUMPCORE;
92 strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
H. Peter Anvin6e16d892008-02-07 00:15:57 -080093 dump.u_ar0 = offsetof(struct user, regs);
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080094 dump.signal = cprm->signr;
95 aout_dump_thread(cprm->regs, &dump);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97/* If the size of the dump file exceeds the rlimit, then see what would happen
98 if we wrote the stack, but not the data area. */
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080099 if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 dump.u_dsize = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
102/* Make sure we have enough room to write the stack and data areas. */
Masami Hiramatsuf6151df2009-12-17 15:27:16 -0800103 if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 dump.u_ssize = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
106/* make sure we actually have a data and stack area to dump */
107 set_fs(USER_DS);
Borislav Petkov7731d9a2010-03-23 13:35:15 -0700108 if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 dump.u_dsize = 0;
Borislav Petkov7731d9a2010-03-23 13:35:15 -0700110 if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 dump.u_ssize = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
113 set_fs(KERNEL_DS);
114/* struct user */
Daisuke HATAYAMA088e7af2010-03-05 13:44:06 -0800115 if (!dump_write(file, &dump, sizeof(dump)))
116 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117/* Now dump all of the user data. Include malloced stuff as well */
Daisuke HATAYAMA05f47fd2010-03-05 13:44:05 -0800118 if (!dump_seek(cprm->file, PAGE_SIZE - sizeof(dump)))
119 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120/* now we start writing out the user space info */
121 set_fs(USER_DS);
122/* Dump the data area */
123 if (dump.u_dsize != 0) {
124 dump_start = START_DATA(dump);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 dump_size = dump.u_dsize << PAGE_SHIFT;
Daisuke HATAYAMA088e7af2010-03-05 13:44:06 -0800126 if (!dump_write(file, dump_start, dump_size))
127 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 }
129/* Now prepare to dump the stack area */
130 if (dump.u_ssize != 0) {
131 dump_start = START_STACK(dump);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 dump_size = dump.u_ssize << PAGE_SHIFT;
Daisuke HATAYAMA088e7af2010-03-05 13:44:06 -0800133 if (!dump_write(file, dump_start, dump_size))
134 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136end_coredump:
137 set_fs(fs);
138 return has_dumped;
139}
140
141/*
142 * create_aout_tables() parses the env- and arg-strings in new user
143 * memory and creates the pointer tables from them, and puts their
144 * addresses on the "stack", returning the new stack pointer value.
145 */
146static unsigned long __user *create_aout_tables(char __user *p, struct linux_binprm * bprm)
147{
148 char __user * __user *argv;
149 char __user * __user *envp;
150 unsigned long __user *sp;
151 int argc = bprm->argc;
152 int envc = bprm->envc;
153
154 sp = (void __user *)((-(unsigned long)sizeof(char *)) & (unsigned long) p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155#ifdef __alpha__
156/* whee.. test-programs are so much fun. */
157 put_user(0, --sp);
158 put_user(0, --sp);
159 if (bprm->loader) {
160 put_user(0, --sp);
Al Viro17580d72009-01-03 07:16:23 +0000161 put_user(1003, --sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 put_user(bprm->loader, --sp);
Al Viro17580d72009-01-03 07:16:23 +0000163 put_user(1002, --sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 }
165 put_user(bprm->exec, --sp);
Al Viro17580d72009-01-03 07:16:23 +0000166 put_user(1001, --sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167#endif
168 sp -= envc+1;
169 envp = (char __user * __user *) sp;
170 sp -= argc+1;
171 argv = (char __user * __user *) sp;
Al Viro17580d72009-01-03 07:16:23 +0000172#ifndef __alpha__
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 put_user((unsigned long) envp,--sp);
174 put_user((unsigned long) argv,--sp);
175#endif
176 put_user(argc,--sp);
177 current->mm->arg_start = (unsigned long) p;
178 while (argc-->0) {
179 char c;
180 put_user(p,argv++);
181 do {
182 get_user(c,p++);
183 } while (c);
184 }
185 put_user(NULL,argv);
186 current->mm->arg_end = current->mm->env_start = (unsigned long) p;
187 while (envc-->0) {
188 char c;
189 put_user(p,envp++);
190 do {
191 get_user(c,p++);
192 } while (c);
193 }
194 put_user(NULL,envp);
195 current->mm->env_end = (unsigned long) p;
196 return sp;
197}
198
199/*
200 * These are the functions used to load a.out style executables and shared
201 * libraries. There is no binary dependent code anywhere else.
202 */
203
204static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
205{
206 struct exec ex;
207 unsigned long error;
208 unsigned long fd_offset;
209 unsigned long rlim;
210 int retval;
211
212 ex = *((struct exec *) bprm->buf); /* exec-header */
213 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
214 N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
215 N_TRSIZE(ex) || N_DRSIZE(ex) ||
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800216 i_size_read(bprm->file->f_path.dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 return -ENOEXEC;
218 }
219
Eugene Teo8454aee2006-09-29 01:59:33 -0700220 /*
221 * Requires a mmap handler. This prevents people from using a.out
222 * as part of an exploit attack against /proc-related vulnerabilities.
223 */
224 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
225 return -ENOEXEC;
226
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 fd_offset = N_TXTOFF(ex);
228
229 /* Check initial limits. This avoids letting people circumvent
230 * size limits imposed on them by creating programs with large
231 * arrays in the data or bss.
232 */
Jiri Slabyd554ed892010-03-05 13:42:42 -0800233 rlim = rlimit(RLIMIT_DATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 if (rlim >= RLIM_INFINITY)
235 rlim = ~0;
236 if (ex.a_data + ex.a_bss > rlim)
237 return -ENOMEM;
238
239 /* Flush all traces of the currently running executable */
240 retval = flush_old_exec(bprm);
241 if (retval)
242 return retval;
243
244 /* OK, This is the point of no return */
Al Viro17580d72009-01-03 07:16:23 +0000245#ifdef __alpha__
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 SET_AOUT_PERSONALITY(bprm, ex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247#else
248 set_personality(PER_LINUX);
249#endif
Linus Torvalds221af7f2010-01-28 22:14:42 -0800250 setup_new_exec(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 current->mm->end_code = ex.a_text +
253 (current->mm->start_code = N_TXTADDR(ex));
254 current->mm->end_data = ex.a_data +
255 (current->mm->start_data = N_DATADDR(ex));
256 current->mm->brk = ex.a_bss +
257 (current->mm->start_brk = N_BSSADDR(ex));
258 current->mm->free_area_cache = current->mm->mmap_base;
Wolfgang Wander1363c3c2005-06-21 17:14:49 -0700259 current->mm->cached_hole_size = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
Al Viro6414fa6a2012-03-05 06:38:42 +0000261 retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
262 if (retval < 0) {
263 /* Someone check-me: is this error path enough? */
264 send_sig(SIGKILL, current, 0);
265 return retval;
266 }
267
David Howellsa6f76f22008-11-14 10:39:24 +1100268 install_exec_creds(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
270 if (N_MAGIC(ex) == OMAGIC) {
271 unsigned long text_addr, map_size;
272 loff_t pos;
273
274 text_addr = N_TXTADDR(ex);
275
Al Virofe30af92009-01-03 07:16:13 +0000276#ifdef __alpha__
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 pos = fd_offset;
278 map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
279#else
280 pos = 32;
281 map_size = ex.a_text+ex.a_data;
282#endif
283 down_write(&current->mm->mmap_sem);
284 error = do_brk(text_addr & PAGE_MASK, map_size);
285 up_write(&current->mm->mmap_sem);
286 if (error != (text_addr & PAGE_MASK)) {
287 send_sig(SIGKILL, current, 0);
288 return error;
289 }
290
291 error = bprm->file->f_op->read(bprm->file,
292 (char __user *)text_addr,
293 ex.a_text+ex.a_data, &pos);
294 if ((signed long)error < 0) {
295 send_sig(SIGKILL, current, 0);
296 return error;
297 }
298
299 flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
300 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
S.Caglar Onur2e50b6c2008-04-29 00:59:26 -0700302 (N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 {
304 printk(KERN_NOTICE "executable not page aligned\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 }
306
S.Caglar Onur2e50b6c2008-04-29 00:59:26 -0700307 if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 {
309 printk(KERN_WARNING
310 "fd_offset is not page aligned. Please convert program: %s\n",
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800311 bprm->file->f_path.dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 }
313
314 if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
315 loff_t pos = fd_offset;
316 down_write(&current->mm->mmap_sem);
317 do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
318 up_write(&current->mm->mmap_sem);
319 bprm->file->f_op->read(bprm->file,
320 (char __user *)N_TXTADDR(ex),
321 ex.a_text+ex.a_data, &pos);
322 flush_icache_range((unsigned long) N_TXTADDR(ex),
323 (unsigned long) N_TXTADDR(ex) +
324 ex.a_text+ex.a_data);
325 goto beyond_if;
326 }
327
328 down_write(&current->mm->mmap_sem);
329 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
330 PROT_READ | PROT_EXEC,
331 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
332 fd_offset);
333 up_write(&current->mm->mmap_sem);
334
335 if (error != N_TXTADDR(ex)) {
336 send_sig(SIGKILL, current, 0);
337 return error;
338 }
339
340 down_write(&current->mm->mmap_sem);
341 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
342 PROT_READ | PROT_WRITE | PROT_EXEC,
343 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
344 fd_offset + ex.a_text);
345 up_write(&current->mm->mmap_sem);
346 if (error != N_DATADDR(ex)) {
347 send_sig(SIGKILL, current, 0);
348 return error;
349 }
350 }
351beyond_if:
352 set_binfmt(&aout_format);
353
354 retval = set_brk(current->mm->start_brk, current->mm->brk);
355 if (retval < 0) {
356 send_sig(SIGKILL, current, 0);
357 return retval;
358 }
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 current->mm->start_stack =
361 (unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
362#ifdef __alpha__
363 regs->gp = ex.a_gpvalue;
364#endif
365 start_thread(regs, ex.a_entry, current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 return 0;
367}
368
369static int load_aout_library(struct file *file)
370{
371 struct inode * inode;
372 unsigned long bss, start_addr, len;
373 unsigned long error;
374 int retval;
375 struct exec ex;
376
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800377 inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379 retval = -ENOEXEC;
380 error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
381 if (error != sizeof(ex))
382 goto out;
383
384 /* We come in here for the regular a.out style of shared libraries */
385 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
386 N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
387 i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
388 goto out;
389 }
390
Eugene Teo8454aee2006-09-29 01:59:33 -0700391 /*
392 * Requires a mmap handler. This prevents people from using a.out
393 * as part of an exploit attack against /proc-related vulnerabilities.
394 */
395 if (!file->f_op || !file->f_op->mmap)
396 goto out;
397
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 if (N_FLAGS(ex))
399 goto out;
400
401 /* For QMAGIC, the starting address is 0x20 into the page. We mask
402 this off to get the starting address for the page */
403
404 start_addr = ex.a_entry & 0xfffff000;
405
406 if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 loff_t pos = N_TXTOFF(ex);
408
S.Caglar Onur2e50b6c2008-04-29 00:59:26 -0700409 if (printk_ratelimit())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 {
411 printk(KERN_WARNING
412 "N_TXTOFF is not page aligned. Please convert library: %s\n",
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800413 file->f_path.dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 }
415 down_write(&current->mm->mmap_sem);
416 do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
417 up_write(&current->mm->mmap_sem);
418
419 file->f_op->read(file, (char __user *)start_addr,
420 ex.a_text + ex.a_data, &pos);
421 flush_icache_range((unsigned long) start_addr,
422 (unsigned long) start_addr + ex.a_text + ex.a_data);
423
424 retval = 0;
425 goto out;
426 }
427 /* Now use mmap to map the library into memory. */
428 down_write(&current->mm->mmap_sem);
429 error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
430 PROT_READ | PROT_WRITE | PROT_EXEC,
431 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
432 N_TXTOFF(ex));
433 up_write(&current->mm->mmap_sem);
434 retval = error;
435 if (error != start_addr)
436 goto out;
437
438 len = PAGE_ALIGN(ex.a_text + ex.a_data);
439 bss = ex.a_text + ex.a_data + ex.a_bss;
440 if (bss > len) {
441 down_write(&current->mm->mmap_sem);
442 error = do_brk(start_addr + len, bss - len);
443 up_write(&current->mm->mmap_sem);
444 retval = error;
445 if (error != start_addr + len)
446 goto out;
447 }
448 retval = 0;
449out:
450 return retval;
451}
452
453static int __init init_aout_binfmt(void)
454{
Al Viro8fc3dc52012-03-17 03:05:16 -0400455 register_binfmt(&aout_format);
456 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457}
458
459static void __exit exit_aout_binfmt(void)
460{
461 unregister_binfmt(&aout_format);
462}
463
464core_initcall(init_aout_binfmt);
465module_exit(exit_aout_binfmt);
466MODULE_LICENSE("GPL");